Methods and systems for implanting a neuromodulation system at a surgically open spinal treatment site

ABSTRACT

The present invention provides a single surgical method, procedure and/or system that creates open visual and physical access to an identified spinal treatment site that initially comprises spinal levels to be treated, wherein the spinal levels comprise at least one dorsal root ganglion. A spinal treatment procedure is performed generally in combination with implantation of a neuromodulation system that may comprise placement of electrical lead(s) on the at least one dorsal root ganglion, wherein each lead is in operative connection with a pulse generator that may also be implanted during the surgical method. Electrical stimulation may be generated with the pulse generator through the electrical leads to the at least one dorsal root ganglion during and/or after the closure of the identified spinal treatment site.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of provisional application62/702,867, filed Jul. 24, 2018 and entitled METHOD FOR IMPLANTING ANEUROMODULATION SYSTEM AT A SPINAL TREATMENT SITE, the contents of whichare hereby incorporated by reference in their entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to a system and/or method for treating chronicspinal pain comprising a surgical procedure combining a spinal proceduresuch as vertebral fusion with implantation of a neuromodulation device,wherein the surgical procedure is conducted with open physical andvisual access to the region of the spine undergoing treatment.

Description of the Related Art

Neuromodulation for the treatment of chronic spinal pain is a procedurethat has been in use for decades. The procedure is generally prescribedto a patient only after they have gone through a spinal procedure thatmay involve vertebral fusion in an effort to mitigate and/or correct thesupposed source of the pain. However, often such spinal procedures donot resolve the pain issues. After weeks, months and perhaps years ofcontinued chronic pain and pain therapy through medications, includingopioids, the patient may finally be prescribed neuromodulation for thetreatment of chronic pain after failed back surgery.

The art does not provide single-surgical-procedure solutions thataddress these issues.

Accordingly, it would be highly advantageous to provide a surgicalmethod and system that enables both a spinal procedure andneuromodulation system implantation within a single procedure.

It would be further highly advantageous to enable full physical andvisual access to the associated spinal treatment site for placement ofthe surgical fusion device and the neuromodulation system.

It would be a further advantage to provide a surgical procedure thatdoes not require advancement of an electrical lead through a patient'sanatomy to reach the ultimate location of therapeutic efficacy.

It would be a further advantage to provide implantation of theneuromodulation system during the open spinal procedure, wherein theneuromodulation system may generate electrical stimulation during and/orafter the surgical procedure.

It would be a further advantage to provide the implanted neuromodulationsystem as described above and for use in generating electricalstimulation only if the patient experiences pain after the surgicalprocedure.

Various embodiments of the present invention address these, inter alia,issues.

The figures and the detailed description which follow more particularlyexemplify these and other embodiments of the invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1A is a block diagram of an embodiment of the present invention.

FIG. 1B is a block diagram of an embodiment of the present invention.

FIG. 2A is a block diagram of an embodiment of the present invention.

FIG. 2B is a block diagram of an embodiment of the present invention.

FIG. 3 is a block diagram of an embodiment of the present invention.

FIG. 4 is a view of an embodiment of the present invention.

FIG. 5 is a view of an embodiment of the present invention.

FIG. 6 is a view of an embodiment of the present invention.

FIG. 7 is a view of an embodiment of the present invention.

FIG. 8 is a view of an embodiment of the present invention.

FIG. 9A is a view of an embodiment of the present invention.

FIG. 9B is a top cross-sectional view of an embodiment of the presentinvention.

FIG. 10A is a view of an embodiment of the present invention.

FIG. 10B is a top cross-sectional view of an embodiment of the presentinvention.

FIG. 11 is a view of an embodiment of the present invention.

FIG. 12 is a view of an embodiment of the present invention.

FIG. 13 is a view of an embodiment of the present invention.

FIG. 14 is a perspective view of an embodiment of the present invention.

FIG. 15 is a perspective view of an embodiment of the present invention.

FIG. 16 is a perspective view of an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Generally, various embodiments of the present invention are based uponthe premise that many patients who suffer from chronic back pain, suchas those who suffer for a long enough period of time or due to theseverity of their particular condition, are also separately sufferingfrom neuropathic pain that cannot be corrected by spinal surgery. Insuch a case it is a misnomer to say that a patient is suffering from“failed back surgery” but more accurately that the back surgery simplydoes not address the neuropathic pain that may have been in place priorto the back surgery.

The present invention provides a method for combining the implantationof a spinal treatment device with the implantation of a neuromodulationdevice, or at least a neuromodulation lead of a neuromodulation device,into a single combination procedure performed at the spinal treatmentsite. The present invention thus provides the potential to treat bothback stabilization issues and neuropathic pain issues in a singleprocedure, with the additional benefit of minimizing the amount of painmedications, including opioids and other pain medications, that apatient may otherwise require to manage chronic back pain.

FIG. 1A is a block diagram of one embodiment of a combination spinalprocedure and neuromodulation procedure (100) wherein neuromodulationtherapy is delivered after completion of the combination procedure.

Initially, the spinal treatment site is identified (102) including thevertebral and spinal levels that are to be treated in the combinationprocedure (100). The target vertebral levels are the vertebral levelsidentified for spinal treatment procedure. The target spinal levels arethe spinal levels identified for the spinal treatment procedure. Thetarget spinal levels may correspond with the target vertebral levels orbe one to two levels above or below the target vertebral levels. Thetarget spinal levels comprise one or more dorsal root ganglia and mayinclude one or both dorsal root ganglion in bilateral relationship toeach other, or may include only a single unilateral dorsal root gangliaat a specific identified spinal level. Additionally, or separately, thetarget spinal levels may be unilateral and may include only a single ormultiple spinal levels in a chained relationship on a single side of thespinal cord.

The method for identifying the target spinal levels is performed usingknown techniques that may comprise a mapping of the dermatome procedureperformed by a medical professional on a patient that has beenidentified to receive a spinal treatment. A result of the mapping of thedermatome is the identification of the specific dorsal root ganglia thatcomprise the target spinal level or target spinal levels. In accordancewith the present invention the target spinal levels more specificallywill include the corresponding dorsal root ganglia at each of thetargeted spinal levels and whether the target spinal level includes abilateral or unilateral treatment of the dorsal root ganglia at each ofthe target spinal levels identified.

The target treatment site comprises the target spinal levels andcorresponding dorsal root ganglia, unilateral or bilateral, that havebeen identified by the above procedure. The target treatment sitefurther may further include the target identified vertebral levels forthe spinal procedure.

Following identification (102) the spinal treatment site is accessed(104) through one or more incisions at or near the spinal treatmentsite. In an open retrograde spinal procedure the incision will enablevisual access to all or of portion of the target vertebral level orlevels and the target spinal level or levels.

Thus, “routing” and “placing”, as used herein in terms of routing andplacing the leads and electrodes, and placing the IPG, are defined aslaying directly on, or positioning directly on or at, the relevantanatomical location with full visualization and physical access andwithout initial epidural access or other internal non-visualizedadvancement from an access point to the relevant anatomical location.Routing and placing as used and defined herein is as a result of theopening created by the “open access” which is defined herein as an opensurgical site, by surgical incision or other means, that allows fullvisual and physical access of the spinal treatment site to enable thedefined routing and placing. “Open access” specifically does not includetraditional epidural access, or any similarly non-open access, whichrequires, inter alia, epidural advancement and/or tunneling to route andplace the leads, electrodes and/or IPG.

The spinal procedure is performed (106) by implanting a spinalstabilization device that may comprise a pair of bilaterally spaced rodseach of the rods affixed to the target vertebrae using at least a pairof pedicle screws to secure each rod to a target vertebrae. A transversebar or plate may extend across the spaced rods to provide further spinalstabilization via the spinal fixation device.

In combination with the spinal procedure at the treatment site, aneuromodulation implantation procedure is also performed at thetreatment site. The neurmodulation implantation procedure includes theplacement of one or more neurostimulation leads at the target spinallevels, and more specifically, at the dorsal root ganglia that comprisethe target spinal levels (108).

The neurostimulation leads may comprise a distal portion having one ormore electrodes positioned at the distal portion. The neurostimulationlead(s) may further comprise a proximal portion capable of coupling toan implantable pulse generator. The neurostimulation lead(s) may furthercomprise one or more electrically conductive wires capable of receivingan electrical signal in a distal portion, when electrically coupled to apulse generator. The neurostimulation lead(s), when coupled to animplantable pulse generator, are then capable of delivering anelectrical signal via the electrode(s) to a target site, such as atarget dorsal root ganglia, when the electrode(s) are placed intherapeutic proximity thereto.

The procedure for placing of the neurostimulation leads may includeplacing the distal segment of one or more neurostimulation leads at thecorresponding one or more target dorsal root ganglia such that the oneor more electrodes of a neurostimulation lead is in therapeuticproximity to the target dorsal root ganglia. Accordingly, when theneurostimulation lead is coupled to an implantable pulse generator andan electrical signal is delivered to the target dorsal root ganglia viathe neurostimulation, the delivered electrical signal results inneuromodulation of the target dorsal root ganglia.

The neurostimulation lead(s) may be fixated (110) in therapeuticproximity to the corresponding target dorsal root ganglia by a varietyof methods. The neurostimulation leads may be anchored using a suture ata distal portion thereof, the neurostimulation leads may be anchored bysuturing a portion of the neurostimulation lead to a vertebral bone orto a portion of the spinal fixation device. Alternatively, theneurostimulation lead(s) may be anchored in place via coupling to animplantable pulse generator (IPG) in a position that provides strainrelief and that otherwise minimizes lead displacement forces.

The implantable pulse generator may be placed/implanted (112) during thespinal procedure in an anatomical location that is dependent upon theparticular treatment procedure performed or dependent upon physicianpreference or dependent upon patient preference or some combinationthereof.

The neuromodulation procedure may further comprise routing of theproximal portion of the neurostimulation lead to an implantable pulsegenerator (114), with operative electrical connection between thelead(s) and the implantable pulse generator. In the situation where thespinal process bone at the treatment site is removed, the implantablepulse generator may be positioned in the carved out portion of thetreatment site at the vertebral level where the bone has been removed.The proximal portion of the one or more neurostimulation leads may thenbe routed to the implantable pulse generator positioned at the treatmentsite.

Once the implantable pulse generator has been placed and coupled to theproximal segment of the neurostimulation leads the one or more incisionsat the spinal treatment site may be closed (116) such as via suture orany other suitable means.

The implantable pulse generator may then be activated to deliver, viathe one or more neurostimulation leads, a neuromodulation therapycomprising electrical stimuli to one or more of the targeted dorsal rootganglia.

In all described embodiments herein, the neuromodulation therapy may bedelivered during the surgical procedure, i.e., when the spinal treatmentsite incisions remain open and/or after closure of the spinal treatmentsite. In some embodiments, the neuromodulation therapy may be deliveredor initiated immediately upon closure of the spinal treatment site ormay be delayed a predetermined period of time. In other embodiments, theneuromodulation therapy may be delivered or initiated only if and whenthe patient experiences back pain after completion of the combinedsurgical procedure.

FIG. 1B provides a block diagram of an embodiment of a procedure 100′comprising an open visual and physical access to the surgical site asdescribed above. However, in this case, the neuromodulation system isplaced and implanted and the access site closed without, at leastinitially, performing the spinal procedure (106). In this embodiment,the benefit of an open visual access site to route leads and placeelectrode(s) is significant to allow the surgeon to ensure properrouting and maximize therapeutic efficacy of the neuromodulationstimulation therapy by, inter alia, proper placement of the electrode(s)in therapeutic proximity with the target dorsal root ganglion/ganglia.Following completion of this procedure, if the patient requires thespinal procedure (106) may be performed, with placement of the relevantfixation rods over or under the previously placed leads as is shownherein in further detail in FIGS. 5-16.

Thus, the spinal level(s), including target dorsal root ganglion/ganglia(DRG(s)) for lead routing and electrode(s) placement are identified at(102). As with FIG. 1A, targeted dorsal root ganglion/ganglia may bebilateral at a single, or more than one, spinal level, or may beunilateral at a single, or more than one, spinal level. The identifyingstep (102) is similar in other respects to FIG. 1A.

After identifying the spinal level(s) and targeted DRG(s), the spinaltreatment site is opened for full visual and physical access to theidentified spinal level(s) (104). As discussed, this open visual andphysical access is highly advantageous, ensuring optimal placement andperformance of the placed and implanted system. Next, at least one leadis placed within the open spinal treatment site (108). Note that becausethe access site is fully open to visual and physical access, there is noneed to “advance” leads through the patient's anatomy. Instead, thesurgeon may physically lay or place the lead(s) in the desired position.Lead(s) comprise a proximal end for operative electrical connection witha pulse generator and a distal end comprising at least one electrode fordelivering an electrical signal to the target DRG. The pulse generatorgenerates an electrical signal that is conducted along the lead and tothe distal placed electrode(s) which then transmit the electrical signalto the target DRG. Leads are fixed 110 as described above in FIG. 1A.

The pulse generator, most typically an implanted pulse generator (IPG)is then placed using the advantages provided by the full visual andphysical access of the opened spinal treatment site at 112. The placedlead(s) are routed to the IPG, wherein the proximal ends of the lead(s)are operatively electrically connected thereto (114) and the access sitemay then be closed at 116. Note that in some embodiments, the IPG may beplaced generally along the midline of the spinal column and may belocated anatomically below the location of the placed electrode(s). Thisconfiguration will generally result in the lead(s) being routed along,but not across, the spinal column and midline thereof. In otherembodiments, the IPG may be placed to one side of the spinal column,resulting in some cases in at least some lead(s) routed across thespinal column and midline thereof.

In one embodiment, neuromodulation stimulation therapy at the identifiedspinal level(s) and to the targeted DRG(s) may be delivered post-closureof the access site 118. In an alternate embodiment, neuromodulationstimulation therapy may also be delivered at the identified spinallevel(s) and to the targeted DRG(s) before closure of the access site tohelp mitigate any pain resulting from the procedure itself. Thispre-closure neuromodulation delivery step is shown as 118′ and withdashed lines as it is an optional alternative embodiment step.

Initially, it is contemplated in this embodiment that a spinal proceduresuch as vertebral stabilization or fusion is not indicated. However,after the access site is closed at 106 and after delivery ofneuromodulation therapy at 118, the patient may develop a need forvertebral stabilization, e.g., fusion. In that case, as shown in dashedlines and as discussed above, identification of the vertebral levels tobe treated is completed at 102′ with subsequent open visual and physicalaccess to the spinal treatment site at 104′. Next, the surgicalprocedure is executed at 106 which may comprise, as is described infra,securement of bilaterally spaced fixation rods across the identifiedvertebral levels and with an optional spanning rod therebetween.Fixation rods may be secured to the identified vertebra with pediclescrews as is well known in the art.

The placement of the fixation rods and optional spanning rod relative tothe previously placed IPG and leads may then be executed as discussedbelow in relation to FIGS. 5-16. In some cases, the fixation rods and/oroptional spanning rod may be placed over the previously placed leads andthe IPG may be disposed below the location of the related electrode(s).In other cases, the fixation rods and/or optional spanning rods may beplaced under the previously placed leads. In some cases, the previouslyplaced IPG may be moved from the original placement and moved inaccordance with the embodiments discussed below, including but notlimited to those embodiments that secure the IPG to one or both of thefixation rods and/or to the spanning rod when present.

FIG. 2A is a block diagram of another embodiment of a combination spinalprocedure and neuromodulation procedure identical to the procedure ofFIG. 1, except that in the procedure of FIG. 2A the lead(s) are routedto the implantable pulse generator after the completion of thecombination spinal procedure and neuromodulation procedure. In thisembodiment of the present invention, the neuromodulation procedureincludes placement of the one or more neurostimulation leads (108) priorto completion of the spinal procedure but may, or may not, includeplacement of the implantable pulse generator (112) or routing andoperative coupling of the neurostimulation leads to the pulse generator(114) prior to completion of the spinal surgery and closure of the site(116).

In such an embodiment, a patient may be implanted with the one or moreneurostimulation leads at the corresponding one or more target dorsalroot ganglia but the delivery of neuromodulation therapy may be delayeduntil a predetermined period of time after completion of the surgicalprocedure and/or until or if the patient experiences back pain after thesurgical procedure is completed, such predetermined period of time mayinclude allowing a patient to recover from the spinal fixation implantprocedure and to determine if the patient needs neuromodulation therapyor if the spinal fixation implant has sufficiently removed the patient'sneed for pain therapy.

Thus, FIG. 2A comprises a combined spinal implant and neuromodulationimplant procedure 200 with the identification (102), access (104),spinal procedure (106), lead placement (108), lead fixation (110) andsite closure (116) steps in the same order and as described above inconnection with FIG. 1. Placement of the IPG (112) and routing andoperative electrical connection of the proximal portion of the lead(s)to the IPG (114) are also as described as above in FIG. 2.

FIG. 2A, however, may delay placement of the implantable pulse generator(112), routing and operative electrical connection of the proximalportion of the lead(s) to an implantable pulse generator (IPG) (114),and delivery or performance of neuromodulation therapy (118) to a pointafter site closure (116). As discussed above, the placement of the IPG(112) with lead routing and operative connection thereto (114) anddelivery of neuromodulation therapy (118) may be delayed for apredetermined time following site closure (116). Alternatively, IPGplacement (112) with lead routing and operative connection thereto (114)and delivery of neuromodulation therapy (118) may be delayed todetermine if the patient's back pain has not been sufficiently mitigatedor treated. In each of these cases, the IPG will be connected withpreviously placed and fixated lead(s) upon the passage of thepredetermined time interval and/or indication that the patient's backpain was not sufficiently treated with the spinal procedure, e.g.,vertebral fusion.

Indeed, in one embodiment of FIG. 2A, it is possible that no IPGplacement (112) will be required if, e.g., the patient's back pain issufficiently treated with the steps 102-116 of FIG. 2. This is theoutcome if the only parameter for continuing the method to implant theIPG with routing and connection of the previously placed and fixatedlead(s) thereto with subsequent initiation and delivery ofneuromodulation therapy (112-118) is whether or not the patient's backpain is sufficiently treated or mitigated.

FIG. 2B method process 200′ is similar to FIG. 2A, except that in FIG.2B, the IPG is placed (112) and leads are routed to the IPG (114) beforeclosing the access site (116). Then, as shown, a predetermined timeinterval may pass before initiating neuromodulation stimulation therapy(118). Alternatively, the patient's pain levels may be monitored postaccess closure and if not sufficiently mitigated, then neuromodulationstimulation therapy may be initiated.

FIG. 3 is a block diagram of an alternative embodiment of a combinationspinal procedure and neuromodulation procedure 300 wherein aneuromodulation therapy is delivered prior to completion of the spinalprocedure. In this embodiment of the present invention, a patient maybeing receiving neuromodulation therapy prior to completion of thespinal procedure. In such an embodiment, the implantable pulse generatoris coupled to the neuromodulation lead and a neuromodulation therapy isprovided prior to closure of the one or more incisions made during thespinal procedure. In such an embodiment, the neuromodulation therapy maybe provided in order to reduce or remove acute pain resulting from thespinal procedure as well as reduce, remove, remediate or minimizechronic pain after completion of the spinal procedure and/or afterrecovery from the spinal procedure.

Thus, procedure 300 is similar to FIG. 1 as it employs the same steps asdescribed in connection with FIG. 1 and in the same order as follows:identification (102); access (104); spinal procedure (106); lead(s)placement (108); lead(s) fixation (110); placement of the IPG (112);routing of the lead(s) and operative electrical connection of theproximal portion of the lead(s) to the placed IPG (114). However,instead of closing the site then performing neuromodulation therapy asin FIG. 1, procedure embodiment (300) reverses these steps as follows:After step (114), neuromodulation therapy is performed (118), then thesurgical site is closed (116).

As discussed above, the embodiment of FIG. 3 may be provided in order toreduce or remove acute pain resulting from the spinal procedure (106) aswell as reduce, remove, remediate or minimize chronic pain aftercompletion of the spinal procedure (106) and/or after recovery from thespinal procedure (106).

In each of the above-described procedures, methods or systems, theplacement of the lead(s) (108) is achieved by therapeutic proximity to atarget dorsal root ganglion. Here, the term therapeutic proximity isdefined as the relationship between the lead(s) and/or electrode(s) ofthe lead(s) and the target dorsal root ganglion such that a therapeuticelectrical signal may be conducted between the lead(s) and/orelectrode(s) and the target dorsal root ganglion. In some casestherefore, therapeutic proximity will be achieved by placing the lead(s)and/or electrode(s) in physical contact with the target dorsal rootganglion, wherein the lead(s) and/or electrode(s) may, or may not be,implanted within the target dorsal root ganglion. A preferred embodimentcomprises a non-implanted physical contacting placement of the lead(s)and/or electrode(s) with the target dorsal root ganglion. Alternatively,no physical contact will be required between the lead(s) and the targetdorsal root ganglion to achieve the required conduction of electricalstimulation signals between the lead(s) and/or electrode(s) and thetarget dorsal root ganglion.

Turning now to FIG. 4, a set of neurostimulation leads L is shown intherapeutic contact with a corresponding set of dorsal root ganglion ata single target identified spinal level S₂ with a bilateral placement ofthe neurostimulation leads L each in therapeutic proximity to acorresponding dorsal root ganglion (DRG) target.

Anatomically, FIG. 4 illustrates four vertebrae (V) each vertebra (V)comprising two superior articular processes (402), a vertebral body(404) with two transverse processes (406) a spinous process (408) andtwo inferior articular processes (410). The superior articular processes(402) are generally shaped to be complementary to and articulatingwithin the inferior articular processes (410). The spinal cord is shownin dashed lines as it traverses through each vertebra (V). A dorsal rootganglion (DRG) (also shown in dashed lines) branches away from thespinal cord, wherein two dorsal root ganglia (DRG) extend bilaterally,i.e., in substantially a transverse direction, away from the spinal cordon either side of the spinal cord and the midline of the spinal cord asshown. Thus, there are two dorsal root ganglia (DRG) associated witheach vertebra (V).

Identification of vertebral levels as discussed above in connection withFIGS. 1-3 may comprise two or more than two vertebra (V) for purposes ofexecuting the spinal procedure, e.g., vertebral fusion procedure. Theskilled artisan will readily understand that the set of 4 vertebrae Vshown in FIG. 4 are merely illustrative and that more, or fewer, than 4vertebrae V may be involved in the various embodiments of the presentinvention.

Identification of spinal levels as discussed in connection with FIGS.1-3 for purposes of executing the placement of the lead(s) L, maycomprise one or both DRG's associated with one vertebra (V), for examplean identified spinal level of S₁, S₂, S₃, or S₄ as those spinal levelsare shown in FIG. 4 Alternatively, the identified spinal levels maycomprise one or two DRG's associated with more than one vertebra (V),e.g., S₁, S₂, S₃, and/or S₄. The identified spinal level(s) may becoincident with, overlapping or offset from, the identified vertebrallevels and/or may located at a vertebra (V) that is not part of theidentified vertebral level(s) V, e.g., V₁, V₂, V₃, and/or V₄ also shownin FIG. 4.

Typically, the identified vertebral levels may comprise vertebrae (V)that are adjacent to or connected with each other. Thus, a typicalidentified vertebral level may comprise exemplary vertebral levels V₁and V₂, which are the subject of the spinal procedure, e.g.,stabilization and/or fusion of vertebrae (V) at the exemplary identifiedvertebral levels V₁ and V₂.

The identified spinal levels S₁, S₂, S₃, and/or S₄ may comprise orinvolve one, or more than one, vertebra V.

In FIG. 4, there is no spinal procedure device shown, only aneuromodulation device or system. Thus, as shown, and in conformancewith the discussion above in connection with FIGS. 1-3, the identifiedspinal level is located at V₂. Further, a neuromodulation device orsystem comprising an IPG that is placed with two electrical leads (L) inoperative electrical connection therewith. The electrical leads (L) arerouted along either side of the spinal column to the identified spinallevel, therefore each lead (L) does not cross the midline of the spinalcolumn. At least one electrode (E) is located at the distal end of eachelectrical lead and is located within therapeutic proximity of thesubject DRG. As also discussed above, FIG. 4 is the result of anopen-access surgical incision that exposes the subject portion of thespinal column, providing the surgeon with physical and visual access tothe relevant vertebrae (V).

As is further shown, the IPG is placed effectively below the placedleads L which facilitates the illustrated routing of the leads (L) alongthe midline of the spinal column. Placement of the IPG in all casesdiscussed herein may be below or above the placed leads L. In addition,the IPG may be placed along the midline of the spinal column asillustrated or may be placed off to one side of the midline of thespinal column as best seen in FIG. 9A which further illustrates at leastsome of the lead(s) L crossing the midline of the spinal column whenthey are routed and the electrodes E placed in therapeutic proximitywith the targeted DRG.

FIG. 5 is an illustration of a spinal treatment site including twospinal fixation rods (450), fixed in place on either side of the midlinewith pedicle screws (452) at opposing ends of the fixation rods (450) asis known in the art, wherein the fixation rods (450) are affixed betweenthe identified vertebral levels V₂ and V₃, thereby effectively fusingthe two associated vertebrae (V) together. The neurostimulation leads Land related electrode(s) E are in routed and placed therapeuticproximity to the DRG's located at the identified target spinal level S₂.In this case, the identified target spinal level S₂ is located at avertebra (V) that is also within the identified target vertebral levelsV₂ and V₃. The IPG is shown as placed at a location that is below therouted and placed leads L and electrodes E. FIG. 5 is also achievedusing an open-access surgical incision that exposes the subject portionof the spinal column, providing the surgeon with physical and visualaccess to the relevant vertebrae (V).

FIG. 6 is an illustration of a spinal treatment site similar to that ofFIG. 5, including a spinal fixation device and neuromodulation device,with the identified vertebral levels shown as V₂ and V₃. However, inthis case one of the identified spinal levels does not involve thevertebrae (V) within the identified vertebral levels. Instead, theidentified spinal levels are shown as S₁, S₂ and S₃, wherein S₁ isoutside of (above) the identified vertebral levels V₂ and V₃.Accordingly, the leads L and related electrode(s) E are shown as placedone spinal level above at S₁ the vertebral levels V₂ and V₃ of thespinal fixation rods 450. The IPG is shown placed below the 3 sets ofleads (L) that are routed and placed in therapeutic proximity to thetargeted DRG's at the identified spinal levels. The leads (L) are routedalong the sides of the spinal cord and are shown as not crossing themidline, though alternate placing of the IPG may result in lead(s) (L)crossing the midline as discussed above.

It will be apparent now to the skilled artisan that alternativeembodiments may be provided with identified spinal level(s) resulting inleads L and related electrode(s) E that are placed one or more spinallevels above the identified vertebral levels. Similarly, an alternativemay comprise identified spinal level(s) resulting in leads L and relatedelectrode(s) E that are placed one or more identified spinal levelsbelow the identified vertebral levels. Consequently, it will beunderstood that embodiments may comprise identified spinal level(s) thatresult in leads (L) and related electrode(s) E that are placed one ormore identified spinal levels above and one or more identified spinallevels below the identified vertebral levels. All of these alternativesmay also comprise identified spinal levels with related leads (L) andelectrode(s) E that are placed within the identified vertebral levels.

FIG. 6 and all alternatives described herein are achieved using anopen-access surgical incision that exposes the subject portion of thespinal column, providing the surgeon with physical and visual access tothe relevant vertebrae (V).

FIG. 7 is similar to the previously described illustrations in FIGS. 5and 6. In this case, however, the spinal treatment site comprises amulti-level spinal fixation device comprising a rod (450) and threepedicle screws (452) securing each rod (450) to vertebrae at theidentified vertebral levels V₂, V₃ and V₄ and neuromodulation leadsplaced at identified spinal levels S₁-S₄ and another lead in therapeuticproximity to the DRG's at the patient's sacrum as shown. Thus, thisembodiment comprises leads (L) with related electrode(s) (E) placed onespinal level above and one spinal level below the vertebral levels ofthe spinal fixation device. In addition, leads (L) and relatedelectrode(s) (E) are routed and placed at spinal levels correspondingwith the identified vertebral levels for the spinal fixation device. Aswith previously described embodiments, the electrode(s) (E) are placedin therapeutic proximity with a dorsal root ganglion (DRG) and theprocedure is executed using an open-access surgical incision that allowsvisual and physical access to the surgical site.

FIG. 8 is an illustration of a spinal treatment site comprising a spinalfixation device comprising fixation rods (450) with pedicle screws (452)securing each rod (450) to vertebral levels V₂ and V₃ and aneuromodulation device comprising 4 sets of bilateral leads (L) withassociated electrode(s) (E) placed at spinal levels S₁-S₄. Accordingly,one pair of bilaterally placed leads (L) and electrode(s) (E) is placedone spinal level above and another pair placed one spinal levels belowthe vertebral levels V₂, V₃ of the spinal fixation device. Though notshown, the neuromodulation lead (1) could also be placed two or morelevels above and/or two or more levels below the spinal levels of thespinal fixation device's rods 450 and screws 452. In this embodiment,additional neurostimulation leads are shown placed bilaterally at thespinal levels S₂ and S₃ corresponding to the spinal fixation device. Inother respects, FIG. 8 is the same as the system shown in FIG. 6 anddescribed in connection therewith, including placement of the IPG, openaccess visualization of the surgical site and placement of the lead(s)(L) and associated electrode(s) (E) in therapeutic proximity of thetargeted DRG.

FIG. 9A is an illustration of a spinal treatment site including a spinalfixation device comprising rods (450) spanning 4 identified vertebrallevels V₁-V₄ and a neuromodulation device comprising an IPG with leads(L) extending transverse to the spinal cord and midline of the spinalcolumn. The neuromodulation leads (L) have a proximal segment extendingin a single sided, unilateral manner with respect to the spinal cordfrom below the at least some of the targeted DRG's in combination with adistal portion of the neuromodulation lead routed for placement intherapeutic proximity with or to the corresponding dorsal root gangliatarget.

In this embodiment, the IPG is placed to one side, or may be external tothe patient's body. As shown, this configuration and embodimentcomprising placement of the IPG to one side of the spinal cord and/ormidline of the spinal column, whether placed internally or externally,results in at least some of the leads (L) being routed across themidline of the spinal column to place the related electrode(s) (E) intherapeutic proximity with the targeted DRG's. Further, as with alldescribed embodiments, the illustrated system is achieved using anopen-access surgical incision that enables visual and physical access ofthe targeted surgical site.

FIG. 9B is a top cross section of a vertebra (V) and related routing ofa lead (L) and placement of electrode(s) (E) from FIG. 9A. Thus, aspinal fixation device comprising a fixation rod (450) andneuromodulation device with a lead placed in therapeutic proximity tothe dorsal root ganglia target. The illustrated configuration isrepresentative of, and may be generally applied to, all embodimentsdescribed herein.

FIG. 10A is an illustration of a spinal treatment site including aspinal fixation device comprising a pair of fixation rods (450) andrelated pedicle screws (452) and neuromodulation device comprising anIPG in operative electrical connection with leads (L) extendingtransforaminally to the corresponding dorsal root ganglia DRG whereinelectrode(s) (E) are placed in therapeutic proximity therewith. FIGS.4-10A show various arrangements of spinal fixation devices andneurostimulation lead placement combinations. In more detail, the leads(L) may take various lead placement paths in order to achieve ormaintain therapeutic proximity to a target dorsal root ganglia. As shownin FIG. 10A, for example, the multi-level spinal fixation device isillustrated with a pedicle screw (452) attached at each identifiedvertebral level, V₁-V₄ in this case. The neurostimulation lead (L)pathways may include a segment of the neurostimulation lead (L)extending between an adjacent pair of pedicle screws (452) on the samefixation rod (450), and the neurostimulation lead (L) may further extendor route underneath the corresponding rod (450) before looping aroundthe corresponding target dorsal root ganglia. The distal segment of theneurostimulation lead (L) comprising associated electrode(s) (E) maythen contact or otherwise be placed in therapeutic proximity to thecorresponding target dorsal root ganglia DRG by looping or curvingaround the target dorsal root ganglia DRG. Placement pathways inaccordance with the present invention may include a segment of a lead Lextending between a pair of adjacent pedicle screws (452) positioned ata target vertebral level and a distal segment of the neurostimulationlead (L) extending to a spinal level at the same level as the vertebrallevel or one spinal level above the target vertebral level or two levelsabove the target vertebral level. Additional placement pathways inaccordance with the present invention include a distal segment of theneuromodulation lead (L) being placed in a retrograde approach to thecorresponding target dorsal root ganglia DRG such that it is looped overthe target dorsal root ganglia DRG, such a placement pathway may extendfrom a segment of the neuromodulation lead L originating from a spinallevel above or a spinal level below the target dorsal root ganglia DRG.

This open-access surgical incision described herein enables full visualand physical access to the system described herein and the targeted DRG,making the described routing of leads (L) and placement of associatedelectrode(s) (E) possible.

FIG. 10B is a top cross section of a spinal treatment site from FIG. 10Aand similar to that of FIG. 9B, including a spinal fixation devicecomprising fixation rods (450) and pedicle screws (452) and a lead (L)with associated electrode(s) (E) placed in therapeutic proximity to thedorsal root ganglia DRG, wherein the lead (L) is routed beneath thefixation rod (450).

In some embodiments described herein, it is contemplated that theimplantable pulse generator (IPG) may be placed within the spinaltreatment site, as described above, or may be placed remotely from thespinal treatment site such as in the flank or buttocks area of thepatient with neuromodulation leads (L), and lead extensions ifnecessary, extending from the spinal treatment site to the remotelocation of the implantable pulse generator (IPG).

Alternatively, it is contemplated that a trial stimulation procedure maybe performed where the neurostimulation leads (L) may be placed intherapeutic proximity with at least one target DRG as described supra,and wherein the placed leads (L) may extend from the treatment site inany of various placement arrangements in accordance with the presentinvention, including but not limited to those discussed above or below,and wherein a proximal end of the leads (L) may extend external to thepatient's body such that an externally positioned pulse generator (EPG)may be electrically operatively coupled to the leads (L) for a trialneuromodulation procedure prior to a full implant of the implantablepulse generator.

Embodiments of an IPG placement are illustrated in FIGS. 11 and 12. FIG.11 is an illustration of an IPG placement site in a flank of a patient.FIG. 12 is an illustration of an IPG placement site at the spinaltreatment site. FIG. 13 is an illustration of an external pulsegenerator (EPG) coupled to neurostimulation leads L extending externalto the patient and electrically coupled with the EPG, and wherein adistal segment of the leads (L) are routed within the patient's body andassociated electrode(s) (E) placed proximal to the target DRG.

FIGS. 14-16 are illustrations of embodiments of an implantable pulsegenerator at a spinal treatment site.

FIG. 14 is an illustration of an implantable pulse generator (IPG)positioned at a spinal treatment site wherein a portion of the vertebralbone at the spinal treatment site has been removed to create space toplace the IPG therein or there along. The IPG has a top (T) and bottomside (B), each having a length and a width. The top and bottom sides (T,B) are generally flat and rectangular in shape, and may include roundedcorners, the top and bottom sides are spaced in a generally parallelrelationship to each other. The IPG further comprises connecting sidesextending between the top and bottom sides, the connecting sides havinga vertical dimension corresponding to the distance between top andbottom sides and the vertical dimension being smaller than either thelength or width of the top and bottom sides. The IPG is dimensioned tofit within the spinal treatment site with a low vertical profile and toprovide a length and width designed to fit within the cleared out boneportion of the spinal treatment site. Thus, in some embodiments, the IPGmay be placed between the fixation rods (450) as shown. In thisembodiment, the IPG is thus placed within the identified vertebrallevels stabilized by the fixation rods (450). A spanning rod (454) isshown that spans the two fixation rods (450). In some embodiments, theIPG may be affixed to one or both fixation rods (450) and/or thespanning rod (454).

In other embodiments, the IPG may be placed in a cleared-out boneportion that is at a vertebral level that is lower, or higher, than theidentified vertebral levels.

FIG. 15 is an illustration of another embodiment of an IPG and placementthereof, wherein the IPG is connected to a spinal fixation devicecomprising two fixation rods (450) and an optional spanning rod (454).The IPG comprises a top (T) and bottom (B) side, each side having alength and a width. The top side (T) may be generally flat andrectangular in shape, and may include rounded corners. The bottom side(B) may comprise a periphery that extends in parallel to the top sidewith the exception of a rod fixation element (456) formed therein thatenables the IPG to be fixated to one of the fixation rods (450). The IPGfurther having connecting sides extending between the top and bottomsides T,B, the connecting sides having a vertical dimensioncorresponding to the distance between top and bottom sides and thevertical dimension being smaller than either the length or width of thetop and bottom sides. In this embodiment, the bottom side (B) has a rodfixation element (456) defined by a curved receptacle portion extendingalong a length of the bottom side, the curved receptacle portion beingconfigured to engage a corresponding curved surface of the rod of thespinal fixation device in order to maintain placement and position ofthe implantable pulse generator when implanted at the spinal treatmentsite. Generally, the shape of the rod fixation element (456) may becomplementary to the shape of the relevant fixation rod (450) to whichit will be affixed. This complementary shaping may be generallycircular, elliptical, curvilinear or any other complementary geometricalshaping that enables the rod fixation element (456) to fit along thefixation rod (450). Thus, the placement of the IPG in this embodiment iswithin the identified vertebral levels.

FIG. 16 is an illustration of another IPG embodiment, and placementthereof, connected to a spinal fixation device comprising fixation rods(450) and pedicle screws (452) with an optional spanning rod (454), allas described supra. The implantable pulse generator has a top and bottomside, each having a length and a width. The top and bottom sides aregenerally flat and rectangular in shape, and may include roundedcorners, the top and bottom sides are spaced in a generally parallelrelationship to each other. The implantable pulse generator furtherhaving connecting sides extending between the top and bottom sides, theconnecting sides having a vertical dimension corresponding to thedistance between top and bottom sides and the vertical dimension beingsmaller than either the length or width of the top and bottom sides. Theimplantable pulse generator further includes one or more rod fixationextension arms (458) extending from at least one corner of at least atop or bottom side of the implantable pulse generator. As shown in FIG.16, a rod fixation extension arm (458) extends from each corner of theIPG to connect to a fixation rod (450), preferably secured byinteraction with a pedicle screw (452) in a generally X-shapedarrangement. The rod fixation extension arm (458) may be affixed orcoupled to the corresponding portion of the rod (450) of the spinalfixation device by fitting over a corresponding pedicle screw (452)segment at the corresponding coupling location such that each of thefour rod extension arms (458) couples to, or is affixed by, a separatepedicle screw (452) in order to maintain the placement of the IPG at thespinal treatment site.

Alternatively, one or more rod fixation extension arms (458) may extendfrom the IPG to connect with the fixation rod(s) (450) and/or pediclescrew(s) (452). Still more alternatively, one or more rod fixationextension arms (458) may extend from the IPG to connect with thespanning rod (454) when spanning rod (454) is present.

Thus, the IPG of FIG. 16 will be placed within the identified vertebrallevels and may be secured and used in combination with the bone-clearingplacement embodiment of FIG. 14 to minimize the vertical rise of theplaced IPG.

The description of the invention and is as set forth herein isillustrative and is not intended to limit the scope of the invention.Features of various embodiments may be combined with other embodimentswithin the contemplation of this invention. Variations and modificationsof the embodiments disclosed herein are possible and practicalalternatives to and equivalents of the various elements of theembodiments would be understood to those of ordinary skill in the artupon study of this patent document. These and other variations andmodifications of the embodiments disclosed herein may be made withoutdeparting from the scope and spirit of the invention.

The invention claimed is:
 1. A method for treating pain generated by apatient's spinal column having a midline with neuromodulationstimulation, comprising: identifying one or more targeted spinal levelsfor neuromodulation stimulation; creating an open access into aresulting spinal treatment site to provide full visual and physicalaccess to at least one dorsal root ganglion at the at least oneidentified targeted spinal level; and placing a neuromodulation systemcomprising: an implantable pulse generator, at least one electrical leadin operative electrical communication with the implantable pulsegenerator and that is routed from the implantable pulse generator to atleast one dorsal root ganglion at each of the one or more target spinallevels, and at least one electrode disposed at a distal end of the atleast one electrical lead, wherein the at least one electrode is placedin therapeutic proximity with each of the at least one dorsal rootganglion at at least one or more target spinal levels; closing the openaccess; and delivering a neuromodulation stimulation therapy to the atleast one dorsal root ganglion with the neuromodulation system afterclosing the open access.
 2. The method of claim 1, further comprisingdelivering a neuromodulation stimulation therapy with theneuromodulation system before closing the open access.
 3. The method ofclaim 1 further comprising conducting a spinal procedure after closingthe open access.
 4. The method of claim 3, wherein the spinal procedurecomprises: identifying two or more targeted vertebral levels forvertebral stabilization; creating an open access into the resultingspinal treatment site to provide full visual and physical access to theidentified targeted vertebral levels and the previously placedneuromodulation system; securing bilaterally spaced fixation rods acrossthe two or more targeted vertebral levels; closing the open access; andcontinuing to deliver neuromodulation stimulation therapy with theneuromodulation system after the open access is closed.
 5. The method ofclaim 4, further comprising delivering neuromodulation stimulationtherapy with the neuromodulation system after the spinal procedure iscomplete and before closing the open access.
 6. The method of claim 4,wherein at least routed one electrical lead is disposed beneath asecured fixation rod.
 7. The method of claim 4, wherein at least oneelectrical lead is disposed above a secured fixation rod.
 8. The methodof claim 4, wherein the placed IPG is positioned between the securedbilaterally spaced fixation rods.
 9. The method of claim 8, wherein theplaced IPG is secured to at least one of the secured bilaterally spacedfixation rods.
 10. The method of claim 4, wherein at least oneidentified targeted spinal level is located at least one level above theidentified targeted vertebral levels.
 11. The method of claim 4, whereinat least one identified targeted spinal level is located at least onelevel below the identified targeted vertebral levels.
 12. The method ofclaim 4, wherein at least one identified targeted spinal level overlapswith the identified targeted vertebral levels.
 13. The method of claim1, further comprising routing at least one electrical lead to cross themidline of the patient's spinal column.
 14. The method of claim 1,further comprising identifying the midline of the patient's spinalcolumn, and placing the implantable pulse generator along the midline ofthe patient's spinal column.
 15. The method of claim 14, furthercomprising routing the at least one electrical lead without crossing themidline of the patient's spinal column.
 16. The method of claim 14,further comprising placing the implantable pulse generator below each ofthe at least one electrodes placed in therapeutic proximity with each ofthe at least one targeted dorsal root ganglion.
 17. The method of claim14, further comprising placing the implantable pulse generator below atleast one of the at least one electrodes placed in therapeutic proximitywith each of the at least one targeted dorsal root ganglion.
 18. Themethod of claim 1, further comprising placing the implantable pulsegenerator on one side of the midline of the spinal column.
 19. Themethod of claim 18, further comprising routing at least one electricallead to cross the midline of the patient's spinal column.
 20. The methodof claim 18, further comprising placing the implantable pulse generatorbelow at least one of the at least one electrodes placed in therapeuticproximity with each of the at least one targeted dorsal root ganglion.21. The method of claim 4, further comprising a spanning rod fixedbetween the two bilaterally spaced fixation rods.
 22. The method ofclaim 4, further comprising affixing the implantable pulse generator tothe spanning rod.